Extract Design Rationale

Turn implementation history into a decision argument. Read references/rationale-matrix.md.

Workflow

1. Inventory candidate decisions in the supplied evidence.
2. Keep only decisions that changed user outcomes, system behavior, risk, cost, delivery, or learning.
3. For each decision, extract:
   • the constraint or problem;
   • the tension between competing goals;
   • the alternatives genuinely considered;
   • why each alternative was rejected or deferred;
   • the final decision and owner;
   • the evidence available at decision time;
   • the observed consequence or metric.
4. Separate contemporary evidence from hindsight.
5. Mark absent alternatives, rationale, ownership, or outcomes as evidence gaps.
6. Rank the records by narrative importance.